Multi-chambered furnace unit



July 23, 1957 J. KGLLING MULTI-CHAMBERED FURNACE UNIT 2 Sheets-Sheet 1Filed Aug. 24, '1953 SN mw mm mm INVENTOR abizazm ffdz/ ATTORNEY J.KbLLlNG MULTI-CHAMBERED FURNACE UNIT July 23, 1957 2 Sheets-Sheet 2Filed Aug. 24, 1953 ATTORNEY United States Patent- O MULTI-CHAMBEREDFURNACE UNIT Johann Kiilling, Oberhausen, Rhineland, Germany, as signorto The Babcock & Wilcox Company, New York, N. Y., a corporation of NewJersey Application August 24, 1953, Serial No. 37 6,020

4 Claims. (Cl. 122-240) The present invention relates to amulti-chambered furnace unit, and more particularly to a fluid heaterfurnace arrangement in which a plurality of primary combustion chambersare provided by cyclone furnaces generally of the construction disclosedin U. S. Patent 2,594,312. Gases resulting from the combustion of fuelin the cyclone chambers are discharged into a secondary chamber which ispartitioned into successive compartments corresponding to the number ofcyclone furnaces.

A multiple cyclone furnace structure of such arrangement provides goodpossibilities for partial load operation since, under those conditions,one or more of the cyclone furnaces can be shut down while the remainingcyclone furnace or furnaces may be maintained in operation at theirrespective full load capacities. However, with prior furnaceconstructions, the feasibility of such operation would ordinarily belimited by the cooling efiect of the secondary chamber through which thecombustion gases and slag must necessarily flow. For variable loadoperation, it is therefore desirable if, in accordance with the presentinvention, the secondary chamber is suitably partitioned so as toprovide a separate secondary chamber gas-receiving compartment for eachcyclone furnace.

Although the partition walls absorb heat from the gases, they also serveto confine the flow of'gases from the respective combustion zones topredetermined regions of the secondary chamber. that the compartments becompletely separated from each other since gases from the respectivecyclone chambers are guided mainly by the upright rear wall portions ofindividual compartments.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descriptivematter in which I have illustrated and described a preferred embodimentof my invention.

Of the drawings:

Fig. 1 is a vertical section, in the plane of symmetry, of a vaporgenerator furnace unit constructed in accordance with the invention; 1

Fig. 2 is a front elevational view of the furnace unit shown in Fig. 1;and

Fig. 3 is a plan section of Fig. 1, taken along line 3--3, in the planeof the cyclone furnace axes.

The illustrative embodiment of the invention thus comprises a pluralityof similar cyclone furnaces 4 which constitute the firing means of avapor generating unit, herein shown only in part. The cyclone furnacesare arranged to discharge into a secondary furnace chamber 5 from whichthe combustion gases are directed upwardly through a tubular slag screen6 and thence into an upper radiation chamber 7 of which only thelowermost portion is shown. After passing through the radiation chamber,the gases are directed in known manner through other fluid heatingcomponents of the unit.

It is not essential however 31 through which slag is discharged, underexclusion ice The cyclone furnaces 4 are suitably arranged at a commonleveland mounted in the front upright wall 8 of the secondary chamber 5,with their axes horizontally disposed and parallel, and inclineddownwardly toward the secondary chamber at a relatively small angle. Thecyclone furnaces 4, of substantially circular cross section about theirlongitudinal axes, are enclosed by circumferential boundary walls 9,10formed with cooling tubes 12 and 13, which, on their furnace sides, arecovered in known manner with refractory material, and on their outersides, with heat insulating material and an exterior metal casing. v

Solid fuel particles, suspended in a high velocity whirling stream ofprimary combustion air, as discharged from a fuel inlet chamber, notshown, are caused to enter each cyclone furnace 4 through an axiallypositioned opening 14 at the outer end. The burning fuel and air arecaused to move in a helical path along the circumferential wall 10,toward an opposite end wall 15 which is formed in common with the inner,front wall 8 of the secondary chamber. The cyclone end wall 15 is formedwith a central, reentrant throat section 16 by which a gas outlet 17 isdefined. A slag outlet 18 is formed in wall 15 adjacent the bottom.Secondary combustion air is supplied from a suitable source throughupright ducts 19, and thence through curved connecting nozzles 21 whichopen tangentially into the respective cyclone chambers 4, in the samedirection as the rotational movement of the burning fuel-air mixturetherein.

The secondary chamber 5 is formed with an upright outer rear wall 23which extends throughout the width of the setting, and which iscontinued upwardly to form the corresponding boundary of the radiationchamber 7. The front wall 3 is extended upwardly and forwardly to formthe inclined front wall 24. Opposing side walls 25 are similarlyextended to form the corresponding lateral walls of chamber 7. Thesecondary chamber 5 is divided by upright partitions 26 into successiverectangular compartments 27 equal in number to the number of cyclonefurnaces, 4, and substantially equal, one to another, in horizontalcross-sectional areas. The partitions 26 extend inwardly from the outerwall 23 and terminate in spaced relation to the inner front wall 8 so asto provide an intercommunicating space 28, between adjoining compartinthe vertical axial plane of the corresponding cyclone furnace. Each slagoutlet 29 opens into a vertical shaft of air, into a water tank, notshown.

The furnace walls, exterior and interior, are formed with cooling tubesthrough which a flow of fluid is maintained, suitably under naturalcirculation, in parallel with the circulatory system of a boilersection, not shown. There is therefore provided a bottom drum 35 towhich liquid, such as water, is supplied through tubes 32 from an upperboiler compartment, not shown. Tubes 36 leading from drum 35 thus serveto conduct water to tubes associated with the conical outer end walls 9of cyclone furnaces 4, whereas other tubes 37 conduct water to tubes 13associated with the cylindrical walls 10; the tubes 13 extendinglongitudinally of walls 10 and connected at one end to an annular inletheader 38' and, at the opposite outer end, to an annular outlet header39, each of which headers is formed with one-half of circular contour,and

- the opposite half of involute contour, so as to conform to thecircumferential curvature of wall 10 and thereby define, in part, aradial space for the assembly of secondary air nozzles 21 in tangentialrelation to the inner wall surface. Certain flow connections, asindicated in part, are arranged to provide for natural circulation ofliquid through the circumferential wall cooling tubes 12 and 13.

Other conductors 41 extend from drum 35 to an intermediate header 42from which tubes 43 extend along the front wall 8 of secondary chamber5, and thereby including portions associated with the cyclone furnacegas outlet nozzles 16; the tubes 43 also continuing upwardly as frontwall-tubes 43 of the radiation chamber 7. Tubes 45, in a separate group,extend from drum 35 along the bottom wall of chamber 5, leaving the slagoutlets 29 open, and continuing upwardly as rear wall cooling tubes 46.The tubes 45' are further extended to form the slag screen 6 after whichthey continue upwardly along the inclined upper front wall 24 ascomponents of the tube group 43. Tubes 47, in an additional row, extendvertically fromdrum 35 as cooling tubes along rearwall 23.

The partition walls 26, between the secondary furnace compartments 27,are formed with cooling tubes 48 which extend upwardly from bottomheaders 49 arranged longitudinally of cyclone furnaces 4, suitably inthe planes of partitions 26. Water is supplied to headers 49 throughconductors 51 which extend from the bottom drum 35. Upright tubes 52, inside walls 25, are connected at their lower ends to longitudinal headers53 to which water is supplied through tubes 54 from drum 35.

In operation, the hot gases of combustion discharging from therespective cyclone chambers 4, through nozzles 16, are thus directedinto the corresponding secondary furnace compartments 27, the gasstreams combining above the partitions and flowing through the slagscreen 6 and thence into the upper radiation chamber 7. The molten slagdischarging from separate cyclone furnaces 4, through slag outlets 18,flows into the respective secondary chamber compartments 27 from whichit is discharged through bottom outlets 29 for ultimate disposal.

While in accordance with the provisions of the statutes I haveillustrated and described herein the best form of the invention nowknown to me, those skilled inthe art will understand that changes may bemade in the form of v the apparatus disclosed without departing from thespirit of the invention covered by my claims, and that certain featuresof my invention may sometimes be used to advantage without acorresponding use of other features.

What is claimed is: v

1. A rnulti-chambered furnace unit comprising a fluid heater furnacehaving as its firing means a plurality of cyclone furnaces providingprimary combustion chambers arranged about horizontally extending axesdisposed in a laterally extending row, said cyclone chambersrespectively having outlet end walls formed with heating gas outlets atone elevation and with slag outlets at a lower elevation, a secondaryfurnace having an upright front wall formed in part in common with saidoutlet end walls of said combustion chambers, upright partition walls ofsolid formation arranged in vertical planes parallel to the axes of saidcombustion chambers and dividing said secondary furnace into successivecompartments arranged to receive gases and slag discharged from therespective combustion chambers, an upright wall arranged in opposingrelation to said front wall and forming the outer wall of said secondaryfurnace, said partition walls extending forwardly from saidouter walland terminating throughout the major portions of their heights in spacedrelation to said upright front wall at positions closely adjacentthereto, each of said compartments having its horizontal depth dimensionconsiderably less than its width and also less than the diameter of thecorresponding cyclone furnace from which said gases are received.

2. A multi-chambered furnace unit comprising a fluid heater furnacehaving as its firing means a plurality of cyclone furnaces providingprimary combustion chambers arranged about horizontally extending axesdisposed in a laterally extending row, said cyclone chambersrespectively having outlet end walls formed with heating gas outlets atone elevation and with slag outlets at a lower elevation, a secondaryfurnace having an upright front wall formed in part in common with saidoutlet end walls of said combustion chambers, upright partition walls ofsolid formation arranged in vertical planes parallel to the axes of saidcombustion chambers and dividing said secondary furnace into successivecompartments adapted to receive gases and slag discharged from therespective combustion chambers, an upright rear wall arranged inopposing relation to said front wall and forming the outer rear walls ofthe respective compartments, said partition walls extending forwardlyfrom said rear wall and terminating throughout the major portions oftheir heights in spaced relation to said upright front wall at positionsclosely adjacent thereto, each of said compartments having itshorizontal depth dimension considerably less than its width, saidcompartments having associated with their respective rear walls aplurality of upright vapor generating tubes which at an elevation abovesaid compartments are arranged in the path of gases discharging from therespective compartments.

3. A fluid heater furnace unit comprising a plurality of cyclonefurnaces formed about horizontally extending axes disposed in alaterally extending row, said cyclone furnaces having outlet end wallsrespectively formed with heating gas outlets at the elevation of saidaxes and with slag outlets at a lower elevation, a secondary furnacehaving an upright front wall formed in part in common with said outletend walls of said cyclone furnaces, upright partition walls of solidformation arranged in substantially vertical planes parallelto the axesof said cyclone furnaces and dividing said secondary furnace intosuccessive compartments adapted to receive heating gases and slagdischarged from the respective cyclone furnaces, each of saidcompartments having its horizontal depth dimension considerably lessthan its width, each of said compartments having a separate slag outletformed in the bottom wall thereof at an elevation below said slagoutlets from said cyclone furnaces, an upright rear wall arranged inopposing relation to said front wall and form- 'ing the outer rear wallsof the respective compartments,

said partition walls extending inwardly from said rear wall andterminating throughout the major portions of their heights at positionsclosely adjacent to said front wall in spaced relation thereto, andupright fluid conducting tubes associated with each of said walls,certain of said tubes at an elevation above said compartments beingextended along, said upright rear wall while others are arranged in theform of a slag screen disposed in the path of upflowinggases'discharging from the respective compartments.

4. A fluid heater furnace unit as defined in claim 3 wherein saidupright front wall is formed with an upper portion inclined forwardlyover said cyclone furnaces, in divergent relation to said upright rearwall of said secondary furnace,-said tubes forming said slag screenhaving portions extended along said inclined front wall portion.

References Cited in the file of this patent V UNITED STATES PATENTS2,285,442 Kerr June 9, 1942 2,357,301 Bailey et al. Sept. 5, 1944FOREIGN PATENTS 512,102 Belgium June 30, 1952 675,410 Great Britain July9, 1952

